JPH03293585A - Heat ray type human body detector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-ray type human body detection device that detects a human body by detecting infrared radiant energy emitted from two human bodies.

``Prior Art'' As a hot-wire type human body detection device of this type, there has been one as shown in Japanese Patent Application Laid-Open No. 1-216292. Fig. 4 shows the whole of the conventional device described in this publication. In the configuration diagram, (L) is the optical system lens, (E,) to (R5)
are detection areas each set by an optical system lens (L), (1) is a pyroelectric infrared sensor that detects the amount of variation in infrared radiation energy in the detection areas (El) to (E,), and (S) is a detection area. The thermoelectric device (CC) that detects the background temperature of the areas (El) to (E,) is a control circuit that outputs a human body detection signal based on the signals from the pyroelectric infrared sensor (1) and the temperature sensor (S).

Fig. 5 is a block diagram of the control circuit (CC) in Fig. 4. In Fig. 5, (1) is a pyroelectric infrared sensor, and this pyroelectric infrared sensor (1) is differentially connected. A pair of heat ray detection elements (CPS) consisting of pyroelectric elements, (
The charge generated by the input of energy at cm) is discharged through the input resistor (R8) with a high resistance value, and the impedance is converted by the field effect transistor (F, ), and the field effect transistor is connected to the DC power supply (+B). (F
Two width resistors (L) connected via l), (
It has a source follower configuration that routes the amplified signal through R3). (2) is an amplifier circuit, and this amplifier circuit (2) includes a first operational amplifier (Op, ), a resistor (R, ) for setting the gain of this operational amplifier (opt), (R
5) and a noise removal capacitor (C, ) (C2), which amplifies the output signal of the pyroelectric infrared sensor (1). (3) is a sensitivity correction circuit, and this sensitivity correction circuit (3) includes a second operational amplifier (OP2) and a resistor (R,) for setting the gain of this operational amplifier (OPT).

(]?7), (+?,), and a field effect transistor (F,) for gain adjustment.
The impedance of the second operational amplifier (O) is varied, and the gain of the second operational amplifier (O□) is varied.
) to convert the output level from (4) is a main comparator circuit, and this main comparator circuit (4) converts the level-converted signal in the sensitivity correction circuit (3) into a reference signal set by a polyimum (V, , ) using a third operational amplifier (opi). The output transistor (Q
l) Output a signal to Nohes. (5) is a radiation temperature measurement circuit configured with a thermomobile (S) as a radiation temperature sensor;
The output signal of S) is input to the non-inverting input terminal (+) of the fourth operational amplifier (OP4), and the output signal of
) and the output terminal between the gain setting resistors (R, , ) to (R,
A correction diode (D) is provided along with 3), and the impedance of this diode (D) changes according to the temperature, making it possible to accurately measure the temperature of the sensor itself. The background temperature of the detection areas (E,) to (R5) is corrected. Then, the impedance of the field effect transistor (F) is varied by the output of the radiation temperature measurement circuit (5), and the operational amplifier (Op.
Next, the operation of varying the gain of z) will be explained. Detection area (E,
-E,) If a human body enters the pyroelectric infrared sensor (]
) outputs a signal corresponding to fluctuations in infrared radiation energy. This signal is amplified by the amplifier circuit (2), and further corrected to an appropriate size according to the background temperature by the sensitivity correction circuit (3) for comparison. The circuit (4) compares it with the preset base voltage. The sensitivity correction circuit (3) corrects the detection area (E) using the temperature sensor (S).

Radiation temperature measurement circuit (5) that measures the background temperature of ~E5)
The amplification degree of the sensitivity correction circuit (3) is changed in response to the output signal of the sensor, thereby satisfying the relationship between the background temperature and the detection sensitivity as shown in FIG. 6.

[Problems to be solved by the invention] The conventional hot-wire human body detection is configured as described above.
Separate sensors were installed to measure infrared radiant energy and to detect variations in infrared radiant energy. For this reason, the cost is high, the external size is large, and each detection area must be made to match, which poses problems in terms of manufacturing and installation.

This invention was made in order to solve the above-mentioned departmental notification, and it is small, inexpensive, easy to manufacture, and requires no adjustment during installation.
Aiming at obtaining a hot-wire type human body detection device capable of highly accurate correction of detection sensitivity ``Means for resolving problems'' The hot-wire type human body detection device according to the present invention has a detection sensor. , an infrared detecting means for outputting a first type component by obtaining a first type component by the infrared radiation temperature in this area, a second type component by an infrared radiation that has entered the area, and superimposing these; a second type component detection means that outputs a second signal when a second type component is included in the first signal; and an infrared radiation temperature that extracts the first type component from the first signal and outputs a third signal. A measuring circuit, and an infrared emitting object recognition means for correcting the second signal based on the third signal and outputting an infrared emitting object detection signal when the magnitude of the corrected signal is equal to or higher than a reference value. It is characterized by:

[Function] The heat-ray type human body detection device of the present invention uses the infrared detecting means to obtain a type 1 component based on the infrared radiation temperature in the area, and enters the area [and is different from the type 1 component due to the infrared radiant]. Obtain the second type component, superimpose them, output as one signal, and further distinguish this signal by the second type component detection means and the infrared radiation temperature measurement circuit to detect the first type component based on the infrared radiation temperature. and the type 2 component caused by the intruder, respectively.

A single infrared detection means can detect infrared radiation temperature and intruders.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Components that are the same as those shown in FIGS. 4 and 6 are given the same reference numerals, and redundant explanations are omitted.

Fig. 1 is an overall configuration diagram of a hot wire type human body detection device according to the present invention. In Fig. 2, (10) is an infrared detection means, and this infrared detection means (10) is located in
An optical system lens (L) that sets ~ (E,), and a thermomobile type infrared sensor that detects infrared radiation energy (
A type 1 component, which is a direct current component, is obtained by the infrared radiation temperature within the detection areas (E,) to (E,) set by the optical system lens (I,).

A second type component, which is an alternating current component, is obtained by an infrared ray emitting object such as a human body that has entered the above area, and a first signal (11) in which these components are superimposed is output. The components are obtained when the infrared radiation traverses multiple areas at different times.

(CCQ) is a control circuit, and this control circuit outputs a second signal (12) when the first signal (10) contains a type 2 component, which is an AC component, as shown in Fig. 2. Second to do
A seed component detection means (7) extracts the first type component, which is a DC component, from the first signal (10) and generates a third signal (13).
and an infrared radiation temperature measurement circuit (8) that outputs.

Based on this third signal (13), the second signal (12) is
and outputs an infrared emitting object detection signal (15) when the magnitude of the corrected signal (14) is equal to or greater than a reference value. The means (16) further includes a sensitivity correction circuit (
3) and a comparison circuit (4).

Next, the operation will be explained.

The detection area (E) set by the optical system lens (L)
When a human body enters the areas l) to (E5), the thermomobile infrared sensor (Tp) detects the infrared radiation energy (DC signal) in the detection areas (El) to (E,) and superimposes it on the detection area (E, ) to (E, ) (alternating current signal portion) are simultaneously converted into electrical signals and output as a first signal (11). The amount of variation in infrared radiant energy is determined by the second type component detection means (7), which detects the variation N(
AC signal) is amplified to an appropriate size and further corrected to an appropriate sensitivity by the sensitivity correction circuit (3).At this time, the thermomobile type infrared sensor (Tp) detects areas (E, ) to ( The infrared radiant energy (DC signal component), which is the background temperature of the same area of E5), is measured by the radiation temperature measurement circuit (8), and the sensitivity correction circuit (3) is measured according to the output signal of the radiation temperature measurement circuit (8). ) is corrected according to the background temperature as shown in Figure 3, and the sensitivity correction circuit (
The comparison circuit (4) compares the output signal of step 3) with a preset reference voltage to determine the presence of a human body.

Note that since the amount of variation in infrared radiant energy (AC signal component) is extremely small compared to the infrared radiant energy (DC signal component), the amount of variation is almost ignored in the radiation temperature measurement circuit (8), and the background temperature is not detected. It has no effect on

Note that - in the above embodiment, a thermomobile type infrared sensor is used as the infrared sensor (Tp), but a thermistor bolometer type infrared sensor may be used.

[Effects of the Invention] As described above, according to the present invention, there is a detection area, the first type component is obtained by the infrared radiation temperature in this area, and the second type component is obtained by the infrared radiation that has entered the area. an infrared detection means for outputting a first signal obtained by superimposing these signals;
a second type component detection means for outputting a signal; an infrared radiation temperature measuring circuit for extracting the first type component from the first signal and outputting a third signal; Since the device is equipped with an infrared emitting object recognition means that outputs an infrared emitting object detection signal when the thickness of the corrected signal is equal to or greater than a reference value, the device can be made smaller and cheaper, and can be Since it becomes a detection area, there is no need for adjustment work during manufacturing and installation, and there is an effect that a highly accurate sensitivity correction can be obtained.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of a hot wire type human body detection device according to an embodiment of the present invention, Fig. 2 is a detailed diagram of the control circuit shown in Fig. 1, and Fig. 3 is a characteristic of background temperature and detection sensitivity shown in Fig. 2. Figure 4 shows the overall configuration of a conventional hot-wire human body detection device, and Figure 5 shows the
FIG. 6 is a detailed diagram of the control circuit shown in the figure, and FIG. 6 is a characteristic diagram of the background temperature and detection sensitivity shown in FIG. In the figure, (7) is the second type component detection means, (8) is the infrared radiation temperature measurement circuit, and (10) is the infrared detection means (
11) is the first signal, (12) is the second signal, (13)
The third signal (14) is a correction signal, and the infrared radiation object detection signal (16) is an infrared radiation object recognition means. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] A first type component having a detection area, obtaining a first type component by infrared radiation temperature in this area, obtaining a second type component by infrared radiation that has entered the area, and superimposing these components. an infrared detection means for outputting a signal; a second type component detection means for outputting a second signal when the first signal contains a second type component; and a second type component detection means for extracting the first type component from the first signal. an infrared radiation temperature measurement circuit that outputs a third signal; and an infrared radiation temperature measurement circuit that corrects the second signal based on the third signal and outputs an infrared radiation detection signal when the magnitude of the corrected signal is greater than or equal to a reference value. A heat-ray human body detection device characterized by comprising an infrared radiation emitting device recognition means.